32 bpp floating point textures

This is VERY preliminary, but it was sufficient for me to get 32 bit floating point textures in a sample app

BUG=skia:
R=bsalomon@chromium.org, bsalomon@google.com

Author: joshualitt@chromium.org

Review URL: https://codereview.chromium.org/359803003

1 files changed, 81 insertions, 0 deletions

diff --git a/tests/FloatingPointTextureTest.cpp b/tests/FloatingPointTextureTest.cpp
new file mode 100644
index 0000000000..d367659a2b
--- /dev/null
+++ b/tests/FloatingPointTextureTest.cpp
@@ -0,0 +1,81 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/*
+ * This is a straightforward test of floating point textures, which are
+ * supported on some platforms.  As of right now, this test only supports
+ * 32 bit floating point textures, and indeed floating point test values
+ * have been selected to require 32 bits of precision and full IEEE conformance
+ */
+#if SK_SUPPORT_GPU
+#include <float.h>
+#include "Test.h"
+#include "GrContext.h"
+#include "GrTexture.h"
+#include "GrContextFactory.h"
+#include "SkGpuDevice.h"
+
+static const int DEV_W = 100, DEV_H = 100;
+static const int FP_CONTROL_ARRAY_SIZE = DEV_W * DEV_H * sizeof(float);
+static const float kMaxIntegerRepresentableInSPFloatingPoint = 16777216;  // 2 ^ 24
+
+static const SkIRect DEV_RECT = SkIRect::MakeWH(DEV_W, DEV_H);
+
+DEF_GPUTEST(FloatingPointTextureTest, reporter, factory) {
+    float controlPixelData[FP_CONTROL_ARRAY_SIZE];
+    float readBuffer[FP_CONTROL_ARRAY_SIZE];
+    for (int i = 0; i < FP_CONTROL_ARRAY_SIZE; i += 4) {
+        controlPixelData[i] = FLT_MIN;
+        controlPixelData[i + 1] = FLT_MAX;
+        controlPixelData[i + 2] = FLT_EPSILON;
+        controlPixelData[i + 3] = kMaxIntegerRepresentableInSPFloatingPoint;
+    }
+
+    for (int origin = 0; origin < 2; ++origin) {
+        int glCtxTypeCnt = 1;
+        glCtxTypeCnt = GrContextFactory::kGLContextTypeCnt;
+        for (int glCtxType = 0; glCtxType < glCtxTypeCnt; ++glCtxType) {
+            GrTextureDesc desc;
+            desc.fFlags = kRenderTarget_GrTextureFlagBit;
+            desc.fWidth = DEV_W;
+            desc.fHeight = DEV_H;
+            desc.fConfig = kRGBA_float_GrPixelConfig;
+            desc.fOrigin = 0 == origin ?
+                kTopLeft_GrSurfaceOrigin : kBottomLeft_GrSurfaceOrigin;
+
+            GrContext* context = NULL;
+            GrContextFactory::GLContextType type =
+                    static_cast<GrContextFactory::GLContextType>(glCtxType);
+            if (!GrContextFactory::IsRenderingGLContext(type)) {
+                continue;
+            }
+            context = factory->get(type);
+            if (NULL == context){
+                continue;
+            }
+
+            SkAutoTUnref<GrTexture> fpTexture(context->createUncachedTexture(desc,
+                                                                             NULL,
+                                                                             0));
+
+            // Floating point textures are NOT supported everywhere
+            if (NULL == fpTexture) {
+                continue;
+            }
+
+            // write square
+            context->writeTexturePixels(fpTexture, 0, 0, DEV_W, DEV_H, desc.fConfig,
+                    controlPixelData, 0);
+            context->readTexturePixels(fpTexture, 0, 0, DEV_W, DEV_H, desc.fConfig, readBuffer, 0);
+            for (int j = 0; j < FP_CONTROL_ARRAY_SIZE; ++j) {
+                REPORTER_ASSERT(reporter, readBuffer[j] == controlPixelData[j]);
+            }
+        }
+    }
+}
+
+#endif